[Lldb-commits] [lldb] b6b3fcd - [lldb] Don't iterate over a std::set<Type*> in SymbolFileDWARF::GetTypes to make it deterministic

[Raphael Isemann via lldb-commits]

Author: Raphael Isemann
Date: 2020-03-02T15:03:45-08:00
New Revision: b6b3fcdcb8cdfb887e26d27bee03b997d2d65888

URL: https://github.com/llvm/llvm-project/commit/b6b3fcdcb8cdfb887e26d27bee03b997d2d65888
DIFF: https://github.com/llvm/llvm-project/commit/b6b3fcdcb8cdfb887e26d27bee03b997d2d65888.diff

LOG: [lldb] Don't iterate over a std::set<Type*> in SymbolFileDWARF::GetTypes to make it deterministic

Summary:
Currently `SymbolFileDWARF::TypeSet` is a typedef to a `std::set<Type *>`.
In `SymbolFileDWARF::GetTypes` we iterate over a TypeSet variable when finding
types so that logic is non-deterministic as it depends on the actual pointer address values.

This patch changes the `TypeSet` to a `llvm::UniqueVector` which always iterates in
the order in which we inserted the types into the list.

Reviewers: JDevlieghere, aprantl

Reviewed By: JDevlieghere

Subscribers: mgrang, abidh, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D75481

Added: 
    

Modified: 
    lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
    lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index c89ccb5bf960..c27b5c4c3495 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -324,10 +324,8 @@ void SymbolFileDWARF::GetTypes(const DWARFDIE &die, dw_offset_t min_die_offset,
       if (add_type) {
         const bool assert_not_being_parsed = true;
         Type *type = ResolveTypeUID(die, assert_not_being_parsed);
-        if (type) {
-          if (type_set.find(type) == type_set.end())
-            type_set.insert(type);
-        }
+        if (type)
+          type_set.insert(type);
       }
     }
 

diff  --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
index a3928c8c3dd4..479235c0d86f 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
@@ -12,11 +12,11 @@
 #include <list>
 #include <map>
 #include <mutex>
-#include <set>
 #include <unordered_map>
 #include <vector>
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SetVector.h"
 #include "llvm/Support/Threading.h"
 
 #include "lldb/Core/UniqueCStringMap.h"
@@ -439,7 +439,7 @@ class SymbolFileDWARF : public lldb_private::SymbolFile,
 
   bool FixupAddress(lldb_private::Address &addr);
 
-  typedef std::set<lldb_private::Type *> TypeSet;
+  typedef llvm::SetVector<lldb_private::Type *> TypeSet;
 
   void GetTypes(const DWARFDIE &die, dw_offset_t min_die_offset,
                 dw_offset_t max_die_offset, uint32_t type_mask,